JP2008064533A - Air current measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air current measuring device manufacturable sufficiently compactly and comparatively inexpensively, capable of measuring a change of an air current sufficiently finely and highly accurately. <P>SOLUTION: This air current measuring device includes a screen 14 for receiving the air current to be measured, a wetting means 24 for wetting the screen with liquid, a thermography means 28 for detecting a temperature distribution in a detection domain 16 of the screen, and an air current calculation means 32 for calculating the air current received by the screen based on a change of a temperature distribution in the detection domain of the screen. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an airflow measurement device that calculates an airflow based on a change in temperature distribution caused by heat of vaporization.

In the following Patent Document 1, in a robot whose face and head are displayed on an electronic display such as a liquid crystal display, in order to eliminate as much as possible a sense of discomfort when a person observes, the face and head of the robot It is disclosed to change the facial expression or move the hair of the head by measuring the wind or airflow acting on the head. With regard to the measurement of airflow, it is disclosed that a sound such as an electret condenser microphone is used to detect sound caused by the airflow, and the wind strength and direction are calculated based on the detected sound.
JP 2005-92675 A

  Thus, the above-described airflow measurement using a microphone requires a large number of microphones to be arranged, which makes the apparatus bulky and increases the manufacturing cost, and reducing the size of the microphone. However, there is a problem that the measurement accuracy of airflow is limited due to physical limitations. Instead of detecting the sound caused by the airflow with a microphone, it is also intended to detect the pressure caused by the airflow with a pressure sensor, or to detect the rotation speed of the micro windmill due to the action of the airflow. When using a micro windmill, there are the same problems as when using a microphone.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is that it can be manufactured in a sufficiently compact and relatively inexpensive manner, and the change in airflow is measured sufficiently finely and with high accuracy. It is an object of the present invention to provide a new and improved air flow measuring device that can be used.

  As a result of diligent research, the inventors of the present invention pay attention to the fact that when an airflow acts on a wet screen, heat of vaporization is generated according to the airflow, and the temperature distribution of the screen changes according to the airflow. It has been found that the main technical problem can be achieved by detecting a change in temperature distribution by means of a thermographic means and calculating an air flow based on the detection.

  That is, according to the present invention, as an airflow measuring device that achieves the main technical problem, a screen that receives an airflow to be measured, a moistening means for moistening the screen with a liquid, and a detection area of the screen An airflow detecting device comprising: a thermographic means for detecting a temperature distribution; and an airflow calculating means for calculating an airflow received by the screen based on a change in temperature distribution in the detection region of the screen. Provided.

  Preferably, it further includes image projection means for projecting an image generated based on the calculated airflow onto the screen. The screen is preferably made of Japanese paper or non-woven fabric. Preferably, the moistening means is composed of a container containing a liquid, and one end edge of the screen is immersed in water contained in the container, and the screen is moistened by capillary action. Preferably, the detection area of the screen extends substantially vertically, and the one edge of the screen is an edge of a portion extending from the upper end of the detection area.

  Although the airflow measuring device of the present invention can be manufactured sufficiently compactly and relatively inexpensively, it can measure changes in the airflow sufficiently finely and with high accuracy.

  Hereinafter, a preferred embodiment of an airflow measurement device configured according to the present invention will be described in more detail with reference to the accompanying drawings.

  FIG. 1 illustrates the main components of a preferred embodiment of an airflow measurement device constructed in accordance with the present invention. The illustrated airflow measurement device includes a support frame 2, and the support frame 2 has a pair of support columns 4 arranged at an appropriate interval. Each of the columns 4 is composed of a rectangular substrate 6 placed on a support plane such as a floor surface, and a column member 8 extending substantially vertically upward from the substrate 6. An upper beam member 10 that extends substantially horizontally is fixed between the upper ends of the pair of column members 8, and an intermediate beam member 12 that extends substantially horizontally is fixed between the upper and lower intermediate portions of the pair of column members 8. Has been.

  A screen 14 is attached to the support frame 2. It is important that the screen 14 can sufficiently wet the detection region 16 (that is, the region defined by the two-dot chain line in FIG. 1) sufficiently. Examples of suitable materials for such a screen 14 include Japanese paper and non-woven fabric. As Japanese paper, for example, Japanese paper for shojis sold under the trade name “Day to Original” by Keiyo Corporation can be conveniently used. As the non-woven fabric, for example, a range filter sold as a product code “2732” by Toyo Aluminum Wheel Products Co., Ltd. can be conveniently used. In the illustrated embodiment, a connecting member 18 extending in the width direction of the screen 14 is fixed to one edge portion of the screen 14, and a connecting member 20 extending in the width direction of the screen 14 is also fixed to the other edge portion. It is fixed. The connecting members 18 and 20 which can be formed from an appropriate synthetic resin or metal plate can be fixed to the screen 14 by an appropriate connecting means such as a double-sided adhesive tape.

  In the illustrated embodiment, a container 24 is fixed between the upper ends of the pair of column members 8 of the support frame 2. The container 24, which can be formed from an appropriate synthetic resin or metal plate, has a substantially semicircular cross-sectional shape, and its upper surface is open. As will become clear from the following description, the container 24 constitutes a moistening means for moistening the screen 14. The connecting member 18 fixed to one edge of the screen 14 is detachably fixed in the container 24 by appropriate connecting means (not shown) such as a fastening screw. The screen 14 extends from one end edge located in the container 24 along the upper half surface of the upper beam member 10 of the support frame 2, and then hangs down substantially vertically between the pair of column members 8. The connection member 20 fixed to the other end edge of the intermediate beam member 12 is connected to the intermediate beam member 12 through elastic shift means 26 which may be a coil spring. Thus, the detection region 16 of the screen 14 is arranged so as to extend substantially vertically into a space defined by the pair of column members 8 and the upper beam member 10 and the intermediate beam member 12 of the support frame 2 and is elastic. The tension means is maintained in a tension state by the elastic tension action of the shift means 26.

  The container 24 contains a liquid that may be clean water. Accordingly, one edge of the screen 14, that is, the edge of the portion extending from the upper end of the detection region 16 of the screen 14 is immersed in the liquid contained in the container 24 together with the connecting member 18. The liquid in the container 24 flows through the screen 14 from one end edge toward the other end edge by capillary action. When the liquid flows over the upper beam member 10 of the support frame 2, the flow of the liquid is promoted by the flow down by weight. Thus, the detection area 16 of the screen 14 is sufficiently moistened.

  Instead of the moistening means as described above using the capillary phenomenon, the moistening means is constituted by other appropriate means such as a desired rose, for example, a sprayer for periodically applying a mist liquid to the detection region 16 of the screen 14. You can also

  Continuing with reference to FIG. 1, the airflow measurement device includes thermographic means 28 for detecting the temperature distribution in the measurement region 16 of the screen 14. The thermographic means 28, which can be composed of a well-known thermographic camera, picks up the detection region 16 of the screen 14 as an image composed of a large number of pixels and detects the temperature of each pixel. As an example of the thermography camera, a thermography camera sold by Nippon Avionics Co., Ltd. under the trade name “Handy Thermo TVS-200” can be cited. Such a thermographic camera can take an image of 240 × 320 pixels 60 times per second, and therefore can detect the temperature of each pixel 60 times per second, and the temperature of each pixel is 0.1 ° C. or less. It can be detected with resolution.

  Referring to FIG. 2 together with FIG. 1, an image captured by the thermographic means 28 is displayed on the liquid crystal monitor 30 provided in the thermographic means 28 and is transmitted to the airflow calculating means 32 as a digital signal. The image displayed on the liquid crystal monitor 30 changes in color according to the temperature in the case of a color image, and the density changes in accordance with the temperature in the case of a monochrome image. FIGS. 3A to 3G illustrate monochrome images displayed on the liquid crystal monitor 30. FIG. In FIGS. 3A to 3G, pixels whose temperature is equal to or higher than the predetermined threshold are displayed in white, and pixels whose temperature is lower than the threshold are displayed in black. Actually, the black color of the pixel whose temperature is less than the threshold value changes in density according to the temperature (the lower the temperature, the higher the density). However, for convenience of illustration, the density difference is ignored in FIGS. 3 (a) to 3 (g). And displayed at a single concentration. As is well known, when an air flow is blown to a specific part in the detection region 16 of the screen 14, the liquid is vaporized and the heat of vaporization is emitted at the air blowing part according to the flow rate (intensity and time) of the blown air. As a result, the temperature of each pixel at the airflow sprayed portion decreases. FIGS. 3A to 3G show the change over time of the pixels in which the temperature drops below the threshold. The airflow is blown to the surface of the screen 14 (that is, the surface opposite to the back surface imaged by the thermographic means 28) or to the back surface.

  As described above, the image captured by the thermographic unit 28 is transmitted to the airflow calculating unit 32 as a digital signal. The airflow calculation means 32 that can be configured from a personal computer analyzes the image change from FIG. 3A to FIG. 3G and identifies the airflow during this time. For example, the moving state of the center of the black pixel in FIGS. 3A to 3G (the center is a center that takes into account the density of each pixel as well as the area of the portion where the black pixel exists) If the change in concentration is appropriately mathematically analyzed, it is possible to grasp the three-dimensional direction of the airflow and the fluctuation of the intensity distribution.

  Continuing the description with reference to FIG. 1 and FIG. 2, the airflow measurement device shown in the figure further includes a video projection means 34 for projecting a required video on the detection area 16 of the screen 14. The output of the airflow calculating means 32, that is, a digital signal for displaying the calculated airflow is supplied to the video projecting means 34 which can be constituted by a known video projector. The image projected by the image projection unit 34 onto the detection area 16 of the screen 14 may be, for example, a display of measured airflow. FIG. 4 illustrates one manner of displaying the measured airflow. In FIG. 4, the arrows indicate the direction of the airflow, and several ellipses indicate how the airflow gradually spreads. The image projected by the image projection unit 34 may be another appropriate image that changes according to the measured airflow, instead of displaying the airflow itself.

  The airflow measurement device configured according to the present invention can be applied to various fields. For example, it can be used as an input means for a computer that is operated by a person with a limb-free hand blowing. In this case, an appropriate image suitable for input is projected onto the detection area 16 of the screen 14. For example, when the operator blows on a specific part, the same input as when a specific input key is pressed is performed. It can be set so that when the blowing region is moved while blowing in a specific area, the same input as when the input mouse is dragged is performed. As an operation means for operating a robot such as a surgical robot by blowing further in addition to the operation by limbs, the airflow measuring device configured according to the present invention can also be used. Furthermore, the air flow measuring device configured according to the present invention may be used in a game machine that displays an appropriate game image in the detection area 16 of the screen 14 and the display image changes appropriately according to the breath blown by the operator. it can.

  The preferred embodiments of the airflow measurement device configured according to the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to such embodiments and departs from the scope of the present invention. It should be understood that various variations and modifications are possible. For example, although Japanese paper and non-woven fabric are exemplified as materials constituting the screen, the screen is composed of other appropriate materials such as a porous ceramic, a porous synthetic resin sheet, or a hydrophilic synthetic resin sheet that can be sufficiently uniformly moistened. You can also In addition, the humidifying means using the capillary phenomenon as the moistening means and the humidifying means constituted by the sprayer are exemplified, but the moistening means from an appropriate liquid supply means for supplying the liquid continuously or intermittently to the screen. Can also be configured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified perspective view showing main components of a preferred embodiment of an airflow measurement device configured according to the present invention. The block diagram which shows a part of component of the airflow measuring apparatus of FIG. The simplified schematic diagram which illustrates the image displayed on the liquid crystal monitor of the thermography means in the airflow measuring apparatus of FIG. The simplified schematic diagram which shows an example of the image | video projected on the detection area | region of the screen in the airflow measuring apparatus of FIG.

Explanation of symbols

2: Support frame 14: Screen 16: Screen detection area 24: Container (wetting means)
28: Thermography means 32: Airflow calculation means 34: Video projection means

Claims (6)

  A screen for receiving an air flow to be measured; a moistening means for moistening the screen with a liquid; a thermographic means for detecting a temperature distribution in a detection area of the screen; and a temperature distribution in the detection area of the screen. An airflow calculating means for calculating an airflow received by the screen based on the change.   The airflow detection device according to claim 1, further comprising image projection means for projecting an image generated based on the calculated airflow onto the screen.   The airflow measuring device according to claim 1 or 2, wherein the screen is made of Japanese paper.   The airflow measuring device according to claim 1 or 2, wherein the screen is made of a nonwoven fabric.   The said wetting means is comprised from the container which accommodated the liquid, The one edge part of this screen is immersed in the water accommodated in this container, and this screen is moistened by capillary action. Airflow measuring device.   The airflow measurement device according to claim 5, wherein the detection area of the screen extends substantially vertically, and the one edge of the screen is an edge of a portion extending from an upper end of the detection area.

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